Variation of surface electric field during geomagnetic disturbed period at Maitri, Antarctica

Abstract

The paper discusses on the variations of the atmospheric vertical electric field measured at sub-auroral station Maitri (70 • 75 ′ S, 11 • 75 ′ E), and polar station Vostok (78.5 • S, 107 • E) during the geomagnetic disturbances on 25-26 January 2006. Diurnal variation of surface electric field measured at Maitri shows a similar variation with worldwide thunderstorm activity, whereas the departure of the field is observed during disturbed periods. This part of the field corresponds to the magnetospheric/ionospheric (an additional generator in the polar regions) voltage generators. Solar wind parameters and planetary indices represent the temporal variation of the disturbances, and digital fluxgate magnetometer variation continuously monitored to trace the auroral movement at Maitri. We have observed that the electrojet movement leaves its signature on vertical and horizontal components of the DFM in addition; the study infers the position of auroral current wedge with respect to Maitri. To exhibit the auroral oval, OVATION model is obtained with the aid of DMSP satellite and UV measurements. It is noted that the Maitri is almost within the auroral oval during the periods of disturbances. To examine the simultaneous changes in the vertical electric field associated with this magnetic disturbance, the dawn-dusk potential is studied for every UT hours; the potential was obtained from Weimer model and SuperDARN radar. The comparison reveals the plausible situation for the superposition of dawn-dusk potential on surface electric field over Maitri. This observation also shows that the superposition may not be consistent with the phase of the electrojet. Comparison of surface electric field at Maitri and Vostok shows that the parallel variation exhibits with each other, but during the period of geomagnetic disturbances, the influence is not much discerned at Vostok.

Anomalous diurnal variation of atmospheric potential gradient and air‐Earth current density observed at Maitri, Antarctica

“…Its speed is generally in the increasing trend between the hours 18 and 24 UT and in decreasing trend between the hours 00 and 06 UT. The response of the AEC and the PG observed at Maitri shows an enhancement during the disturbed geomagnetic activity [ Anil Kumar et al ., , ; Jeni Victor et al ., ]. All these observations reported the enhancement of the atmospheric electricity parameters to occur during the hours between 18 and 24 UT.…”

Review of Relationships Between Solar Wind and Ground-Level Atmospheric Electricity: Case Studies from Hornsund, Spitsbergen, and Swider, Poland

“…Later, when previously unattainable information on SW-M-I interactions was introduced to the analysis, the observations begun to reveal cases of some repeatable E z responses to these changes with a regular character. Findings from the Arctic, described in greater detail below, were extended by analysis of atmospheric electric recordings in the Antarctic, particularly at the South Pole and Vostok stations (Bering et al 1988(Bering et al , 1991Burns et al 1995;Tinsley et al 1998;Frank-Kamenetsky et al 1999, 2001Corney et al 2003;Troshichev 2004;Lukianova et al 2011;Victor et al 2015). In particular, the Antarctic Plateau climate with predominant fair-weather periods made it possible to obtain quickly a large number of reliable E z data which were statistically analysed, and some statistically significant correlations between the chosen parameters have been found there in the last decades.…”

India's Contribution to Geomagnetism and Allied Studies in Antarctica-A Review

“…This behaviour was ascribed to regional phenomena like katabatic winds bringing in space charge from the polar plateau. Victor et al (2015) discussed the variations of the atmospheric vertical electric field measured at Maitri and the polar station, Vostok (78.5 o S, 107 o E), during the geomagnetic disturbances on 25-26 January 2006. The departure of the field at Maitri, as observed in Fig.…”